advance guard airhead ancestor announcer antecedent avant-garde battle line beachhead bellwether bridgehead buccinator bushwhacker explorer farthest outpost first line forebear forefront foregoer forerunner front front line front rank front runner frontiersman fugleman groundbreaker guide harbinger herald innovator lead runner leader line messenger outguard outpost pathfinder pioneer point precedent precursor predecessor railhead scout spearhead stormy petrel trailblazer trailbreaker van vanguard vaunt-courier voortrekker